USB Device Controller

12.6.3.8Setup Active (SA)

The Setup Active bit indicates that the current packet in the FIFO is part of a USB setup command. This bit generates an interrupt and becomes active at the same time as UDCCS0[OPR]. Software must clear this bit by writing a 1 to it. Both UDCS0[OPR] and UDCCS0[SA] must be cleared.

12.6.4UDC Endpoint x Control/Status Register (UDCCS1/6/11)

UDCCS1/6/11, shown in Table 12-15, contains 6 bits that are used to operate endpoint(x), a Bulk IN endpoint).

Table 12-15. UDCCS1/6/11 Bit Definitions

0x 4060_0014

UDCCS1

 

0x 4060_0028

UDCCS6

USB Device Controller

0x 4060_003C

UDCCS11

 

Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8

reserved

X X X X X X X X X X X X X X X X X X X X X X X X

7 6 5 4 3 2 1 0

TSP reserved FST SST TUR FTF TPC TFS

0 0 0 0 0 0 0 1

Bit

Name

Description

 

 

 

31:8

reserved

 

 

 

7

TSP

Transmit short packet

1 = Short packet ready for transmission.

 

 

 

 

 

6

reserved

 

 

 

5

FST

Force STALL

1 = Issue STALL handshakes to IN tokens.

 

 

 

 

 

4

SST

Sent STALL

1 = STALL handshake was sent.

 

 

 

 

 

3

TUR

Transmit FIFO underrun

1 = Transmit FIFO experienced an underrun.

 

 

 

 

 

2

FTF

Flush Tx FIFO

1 = Flush Contents of TX FIFO

 

 

 

 

 

 

 

Transmit packet complete

1

TPC

0 = Error/status bits invalid.

 

 

1 = Transmit packet has been sent and error/status bits are valid.

 

 

 

 

 

Transmit FIFO service

0

TFS

0 = Transmit FIFO has no room for new data

 

 

1 = Transmit FIFO has room for at least 1 complete data packet

 

 

 

12.6.4.1Transmit FIFO Service (TFS)

The transmit FIFO service bit is active if one or fewer data packets remain in the transmit FIFO. TFS is cleared when two complete packets of data remain in the FIFO. A complete packet of data is signified by loading 64 bytes of data or by setting UDCCSx[TSP].

Intel® PXA255 Processor Developer’s Manual

12-27

Page 429
Image 429
Intel PXA255 manual UDC Endpoint x Control/Status Register UDCCS1/6/11, Setup Active SA, Transmit Fifo Service TFS